Journal cover Journal topic
Natural Hazards and Earth System Sciences An interactive open-access journal of the European Geosciences Union
doi:10.5194/nhess-2017-136
© Author(s) 2017. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
10 Apr 2017
Review status
This discussion paper is under review for the journal Natural Hazards and Earth System Sciences (NHESS).
Surface water floods in Switzerland: what insurance claim records tell us about the caused damages in space and time
Daniel B. Bernet1, Volker Prasuhn2, and Rolf Weingartner1 1Institute of Geography & Oeschger Centre for Climate Change Research & Mobiliar Lab for Natural Risks, University of Bern, Bern, Switzerland
2Agroscope, Research Division, Agroecology and Environment, Zurich, Switzerland
Abstract. Surface water floods (SWFs) have received increasing attention in the recent years. Nevertheless, we still know relatively little about where, when and why such floods occur and cause damages, largely owed to a lack of data, but to some degree also because of terminological ambiguities. Therefore, in a preparatory step, we summarize related terms and identify the need for unequivocal terminology across disciplines and international boundaries in order to bring the science together. Thereafter, we introduce a large (n = 63'117), long (10–33 years) and representative (48 % of all Swiss buildings covered) data set of spatially explicit Swiss insurance flood claims. Based on registered flood damages to buildings, the main aims of this study are twofold: First, we introduce a methodology to differentiate damages caused by SWFs and fluvial floods based on the geographical location of each damaged object in relation to flood hazard maps and the hydrological network. Second, we analyze the data with respect to their spatial and temporal distributions aimed at quantitatively answering the fundamental questions of how relevant SWF damages really are, as well as where and when they occur in space and time.

This study reveals that SWFs are responsible for at least 45 % of all flood damages to buildings and 23 % of the associated direct tangible losses, whereas lower losses per claim are responsible for the lower loss share. The Swiss lowlands are affected more heavily by SWFs than the alpine regions. At the same time, the results show that the damages are not evenly distributed within each region either. By far the most SWF damages occur during summer in almost all regions. The normalized damages of all regions show no significant upward trend of SWF damages between 1993–2013. We conclude that SWFs are in fact a highly relevant process in Switzerland that should receive similar attention like fluvial flood hazards. Moreover, as SWF damages almost always coincide with fluvial flood damages, we suggest to consider SWFs, just as fluvial floods, as integrated processes of our catchments.


Citation: Bernet, D. B., Prasuhn, V., and Weingartner, R.: Surface water floods in Switzerland: what insurance claim records tell us about the caused damages in space and time, Nat. Hazards Earth Syst. Sci. Discuss., doi:10.5194/nhess-2017-136, in review, 2017.
Daniel B. Bernet et al.
Daniel B. Bernet et al.
Daniel B. Bernet et al.

Viewed

Total article views: 211 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
160 44 7 211 1 6

Views and downloads (calculated since 10 Apr 2017)

Cumulative views and downloads (calculated since 10 Apr 2017)

Viewed (geographical distribution)

Total article views: 211 (including HTML, PDF, and XML)

Thereof 205 with geography defined and 6 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 26 Apr 2017
Publications Copernicus
Download
Short summary
To quantify the relevance of surface water floods in Switzerland, we introduce and analyze an exhaustive set of insurance flood damage claims. First, we present a method to classify such claims and then, we analyze the classified data with respect to space and time. The results reveal that just as fluvial floods are responsible for vast damages in Switzerland, so too are surface water floods. Accordingly, surface water floods should receive similar attention like fluvial floods.
To quantify the relevance of surface water floods in Switzerland, we introduce and analyze an...
Share